2
Functional Subsystems
This microscope specific modules
projector
Projector system
Extra modules
Design of the modular two-photon microscope with photostimulation implemented in Naumann Lab
NL_2p1 content
NL_2p1 overview

Projector system

  • We're positioning the projector outside of the microscope enclosure , because it generates quite a lot of heat, which is sufficient to cause mild melting of agarose during experiments. Alternatively, the projector could have been cooled down by the water cooling system. But the current solution is cleaner and simpler.
  • The 3D model below misrepresents the mirror reflecting light from the projector onto the screen under the dish with zebrafish. It appears dichroic, which would work, but in reality we're using a simpler front surface mirror (important, as with the back surface mirror, we'd have double reflection and not sharp image).
  • In the enclosure wall, there is a hole made exactly to fit an SM1 Thorlabs lens tube. This tube holds a 532nm long pass filter, and 200mm plano-convex spherical lens (projector's adjusting focal range doesn't cover the particular distance between the projector and the sample). Notice, that these components are currently not shown in the 3D model.
  • See exper tab in NL-2p1_asmbly.xlsx for parts list.

  • To minimize light-induced noise during two-photon imaging, we modified an AAXA Technologies P300 Pico projector by isolating the red LED within its LED engine. This modification, coupled with a custom-built electronic circuit controlled by the NI DAQ card (not shown), enables precise sub-microsecond timing of the LED's illumination. This precise control allows us to strobe the projected light, synchronizing it with the flyback periods of the galvo mirrors in the two-photon microscope. By illuminating only during the galvo mirror's deceleration and acceleration phases, we avoid light contamination during image acquisition. The typical flyback duty cycle, approximately 20%, permits sufficiently frequent illumination to maintain a perceptually smooth projected image.
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Projector system